Evaluation of dietary yellow loess as an antibiotic replacer in Rainbow trout, Oncorhynchus mykiss and Japanese eel, Anguilla japonica

Abstract

본 실험은 무지개 송어와 뱀장어에 있어서 항상제 대체제로서 사료 내 황토의 효과를 평가하기 위해 수행하였다. 실험 1에서는, 평균무게 39.4 ± 1.6g (mean ± SD)인 무지개 송어를 대상으로 실험사료는 항생제 및 항생제 대체물질인 황토가공신소재의 첨가수준에 따라 총5개 실험구(CON, YL0.5, YL1.0, YL2.0, OTC ; CON: 대조구, YL: 황토가공신소재(%), OTC: Oxytetracycline)를 사용하였다. 12주간 사육실험을 토대로 한 성장요인결과 , 증체율과 일간성장률에 있어서 YL1.0, YL2.0과 OTC 실험구는 CON 실험구에 비해 유의적으로 높은 값을 나타냈으며 YL0.5 실험구와는 유의적인 차이가 없었다. 이러한 결과를 토대로, 무지개 송어를 사육하는데 있어 사료내 1.0~2.0%의 황토의 첨가가 OTC를 대체할 수 있을 것으로 판단되었다. 실험 2에서는, 평균무게 11.5 ± 0.4g (mean ± SD)인 뱀장어를 대상으로 실험사료는 총6개 실험구(CON, YL0.5, YL1.0, YL2.0, OTC, AMX ; CON: 대조구, YL: 황토가공신소재(%), OTC: Oxytetracycline, AMX: Amoxicillin)를 사용하였다. 12주간의 사육실험을 토대로 한 성장요인결과 , 증체율과 일간성장률에 있어서 YL2.0과 OTC 실험구는 CON과 YL0.5에 비해 유의적으로 높은 값을 나타냈으며 YL0.5, YL1.0과 AMX 실험구간 또는 YL1.0, YL2.0, OTC와 AMX 실험구 간에는 유의적인 차이가 없었다. 이러한 결과를 토대로, 치어기 뱀장어를 사육하는데 있어 사료내 1.0~2.0%의 황토의 첨가가 OTC 및 AMX를 대체할 수 있을 것으로 판단되었다.

Two experiments were conducted to evaluate the effects of dietary yellow loess as an antibiotic replacer in rainbow trout, Oncorhynchus mykiss and Japanese eel, Anguilla japonica. In the first experiment, rainbow trout averaging 39.4 ± 1.6g (mean±SD) were fed one of the Five experimental diets; Five experimental diets were formulated to contain no antibiotics or yellow loess (CON), three graded levels of yellow loess 0.5 (YL0.5), 1.0 (YL1.0) and 2.0%(YL2.0) and oxytetracycline at 0.5%(OTC). At the end of the feeding trial, weight gain (WG) and specific growth rate (SGR) from fish fed CON diet were lower than those from fish fed YL1.0, YL2.0 or OTC diets. Lysozyme activities from fish fed YL2.0 were higher than those from fish fed CON diet. Lysozyme activities from fish fed YL2.0 were higher than those from fish fed CON diet. Superoxide dismutase (SOD) activities from fish fed YL1.0 and YL2.0were higher than those from fish fed CON diet. The results indicated that, dietary yellow loess at 1.0 to 2.0% could be an alternative of oxytetracycline in rainbow trout. In the second experiment, Japanese eel averaging 11.5 ± 0.4g (mean±SD) were fed one of the Six experimental diets; Six experimental diets were formulated to contain no antibiotics or yellow loess (CON), three graded levels of yellow loess 0.5 (YL0.5), 1.0 (YL1.0) and 2.0% (YL2.0), oxytetracycline at 0.5% (OTC) and amoxicillin at 1.0% (AMX). At the end of the feeding trial, weight gain (WG) and specific growth rate (SGR) from fish fed CON and YL0.5 diets were lower than those from fish fed YL2.0 or OTC diets. Lysozyme activities from fish fed YL2.0, OTC and AMX were higher than those from fish fed CON and YL0.5 diets. Superoxide dismutase (SOD) activities from fish fed CON were lower than those from fish fed different treatment diets. The results indicated that, dietary yellow loess at 1.0 to 2.0% could be an alternative of oxytetracycline in rainbow trout.